U.S. patent application number 09/987320 was filed with the patent office on 2002-05-16 for gelling agents and gels containing them.
This patent application is currently assigned to University of Otago. Invention is credited to Beyer, Richard, Silcock, Patrick J..
Application Number | 20020058097 09/987320 |
Document ID | / |
Family ID | 26651746 |
Filed Date | 2002-05-16 |
United States Patent
Application |
20020058097 |
Kind Code |
A1 |
Beyer, Richard ; et
al. |
May 16, 2002 |
Gelling agents and gels containing them
Abstract
The invention relates to modified casein gelling agents, gels
and processes for preparing them. The modified casein gelling agent
is casein in which the native structure has been disrupted.
Inventors: |
Beyer, Richard; (Lami, Suva,
FJ) ; Silcock, Patrick J.; (Dunedin, NZ) |
Correspondence
Address: |
NIXON & VANDERHYE P.C.
8th Floor
1100 North Glebe Road
Arlington
VA
22201-4714
US
|
Assignee: |
University of Otago
|
Family ID: |
26651746 |
Appl. No.: |
09/987320 |
Filed: |
November 14, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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09987320 |
Nov 14, 2001 |
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09367501 |
Nov 29, 1999 |
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09367501 |
Nov 29, 1999 |
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PCT/NZ98/00019 |
Feb 16, 1998 |
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Current U.S.
Class: |
426/590 |
Current CPC
Class: |
A23P 10/30 20160801;
A23K 50/80 20160501; A61K 47/42 20130101; A23L 29/281 20160801;
A23J 3/10 20130101 |
Class at
Publication: |
426/590 |
International
Class: |
A23L 002/00 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 17, 1997 |
NZ |
314255 |
Claims
What we claim is:
1. A gelling agent which comprises modified casein, the native
structure of the casein having been disrupted sufficiently to cause
a composition to which the casein is added in use to gel.
2. A gelling agent according to claim 1 which comprises a
dispersion of modified casein in water and a plasticiser.
3. A gelling agent according to claim 2 in which the plasticiser is
glycerol.
4. A method of preparing a gelling agent which comprises the steps
of: (a) forming a dispersion comprising casein and water; and (b)
heating the dispersion for a sufficient time and to a sufficient
temperature to disrupt the native structure of the casein.
5. A method according to claim 4 in which the dispersion is heated
to a temperature of 95.degree. C. or above.
6. A method according to claim 5 in which the dispersion is heated
to a temperature of at least 100.degree. C.
7. A method according to claim 5 in which the dispersion is heated
to a temperature of at least 110.degree. C.
8. A method according to claim 7 in which the dispersion is
maintained at a temperature of at least 110.degree. C. for at least
five minutes.
9. A modified-casein gelling agent which is obtainable by a method
as claimed in any one of claims 4 to 8.
10. A modified casein gelling agent which is obtained by a method
as claimed in any one of claims 4 to 8.
11. A process of preparing a gelled product which comprises adding
a gelling agent as defined in any one of claims 1 to 3, 9 and
10.
12. A process of preparing a gelled product which involves the use
of casein as a gelling agent.
13. A gelled product which includes a gelling agent as defined in
any one of claims 1 to 3, 9 and 10.
14. A gelled product according to claim 13 which is a food
product.
15. A gelled product according to claim 13 which is a delivery
matrix which comprises (a) a matrix which includes the modified
casein; and (b) an active agent incorporated in the matrix.
16. A method of preparing a gelled product which comprises the
following steps: (a) forming a dispersion comprising casein and
water; (b) heating the dispersion for a sufficient time and to a
sufficient temperature to disrupt the native structure of the
casein; and (c) removing the source of heat, adding other gellable
components and allowing the resulting mixture to set into a
gel.
17. A method according to claim 16 wherein the dispersion also
comprises a plasticiser and a buffer to maintain the pH in the
range of about 6.1 to about 10.1.
18. A method according to claim 16 or claim 17 wherein the
dispersion is heated to temperature of at least 95.degree. C.
19. A method according to claim 18 wherein the dispersion is heated
to a temperature of at least 100.degree. C.
20. A method according to claim 18 wherein the dispersion is heated
to a temperature of at least 110.degree. C.
21. A gelled product which is the product of a method as claimed in
any one of claims 16 to 20.
Description
[0001] This invention relates to gelling agents, gels and to
processes for preparing them. It also relates to products
comprising the gels, in particular matrices for delivering active
agent and food products.
BACKGROUND
[0002] Gels are formed from macromolecular hydrocolloids and have
the ability to form non-deformable structures with low impact
resistance. The classical gelling agent, which has been most widely
studied, is gelatine. This is also the only known food grade
hydrocolloid which is a protein. Gelatine is, nutritionally, a low
quality protein and gels incorporating it have the disadvantages
that they tend to harden on storage and may develop undesirable
textural properties. Gelatine may also have negative religious
and/or health connotations for some consumers, as it is produced in
a manner destructive of animals and there may also be concerns
arising from a perceived link with Transmissible Spongiform
Encephalopathies such as Bovine Spongiforms Encephalopathy or
Creutzfeld-Jacob Disease
[0003] It is an object of the present invention to provide a
gelling agent which will go some way towards overcoming the above
disadvantages, or at least to provide the public with a useful
choice.
SUMMARY OF THE INVENTION
[0004] In a first aspect the present invention may broadly be said
to consist in a gelling agent which comprises modified casein, the
native structure of the casein having been disrupted sufficiently
to cause a composition to which the casein is added in use to
gel.
[0005] Preferably, the gelling agent comprises a dispersion of
modified casein in water and a suitable plasticiser, preferably
glycerol.
[0006] In a further aspect the present invention provides a method
of preparing a gelling agent which comprises the steps of:
[0007] (a) forming a dispersion comprising casein and water;
and
[0008] (b) heating the dispersion for a sufficient time and to a
sufficient temperature to disrupt the native structure of the
casein.
[0009] In another aspect the present invention may broadly be said
to consist in a process of preparing a gelled product which
comprises adding a gelling agent as defined above to a gellable
composition.
[0010] In yet a further aspect the invention may broadly be said to
consist in a process of preparing a gelled product which involves
the use of casein as a gelling agent.
[0011] In still a further aspect the present invention may broadly
be said to consist in a gelled product which includes a gelling
agent as defined above.
[0012] In preferred embodiments, the gelled product is a food
product.
[0013] In other alternative preferred embodiments, the gelled
product is a delivery matrix which comprises (a) a matrix which
includes the modified casein; and (b) an active agent incorporated
in the matrix.
[0014] In yet a further aspect the present invention may broadly be
said to consist in a method of preparing a gelled product which
comprises the following steps:
[0015] (a) forming a dispersion comprising casein and water;
[0016] (b) heating the dispersion for a sufficient time and to a
sufficient temperature to disrupt the native structure of the
casein; and
[0017] (c) removing the source of heat, adding other gellable
components and allowing the resulting mixture to set into a
gel.
[0018] Preferably, the dispersion also comprises a plasticiser
(preferably glycerol) and a suitable buffer to maintain the pH in
the range of about 6.1 to about 10.10.
DESCRIPTION OF THE INVENTION
[0019] As outlined above, the invention relates generally to gelled
products and to macromolecular gelling agents used in their
preparation.
[0020] The ability of a macromolecule to gel depends on interaction
between molecules at restricted points along the macromolecule.
Portions of the molecule that do not interact disperse in the
continuous phase (usually water). Energy is usually required to
disrupt the native structures of hydrocolloids. For instance,
gelatine is manufactured by applying heat to collagen. The
applicants have discovered that the native structure of casein can
be disrupted sufficiently for gel formation. This can be achieved,
for example, by heating, generally to a temperature of about
95-110.degree. C. or above. It is this finding by the applicants
which forms the basis for the present invention.
[0021] In a first aspect, the invention provides a gelling agent
which comprises modified casein, in which the native structure of
the casein has been disrupted sufficiently to cause a composition
to which the casein is added to gel. The gelling agent preferably
comprises a dispersion of the modified casein in a suitable
plasticiser (preferably glycerol or glycerol combined with
propylene glycol (1,2-propanediol) and water, although other forms
of the modified casein are by no means excluded.
[0022] The gelling agents of the present invention have a number of
potential applications. For example, in some embodiments of the
invention, the gelling agents may be used in food products. In
other embodiments the gelling agents may be used in preparing
non-edible gels. For example, they may form part of a delivery
matrix in which a matrix containing the modified casein
encapsulates an active agent.
[0023] The preferred formulation of a particular gelling agent of
the present invention will depend on the desired end use of the
gel.
[0024] For example, alteration of the amount of plasticiser, if any
present will change the characteristics of the resultant gel.
Similar changes can be effected by changing the identity of the
plasticiser. By way of illustration, using 1,2-propanediol as a
plasticiser instead of, or partially instead of glycerol, results
in a softer gel with a lower melting point. This may be desirable
for some applications, for example where volatiles are to be
entrapped or encapsulated by the gel matrix.
[0025] It is also possible to produce a lower melting point gel
matrix through the addition of excess water during formation of the
matrix. The excess water can then be removed again after the
volatiles are encapsulated by gently drying over silica.
[0026] A still further approach to modifying the properties of the
gel matrix is to replace a small amount of modified casein with
gelatine (between 10% and 20%). This produces a lower melting point
gel matrix which is softer than the equivalent matrix using casein
alone.
[0027] Various embodiments of the invention are described in more
detail below.
[0028] Food/confectionery applications
[0029] As noted above, in some preferred embodiments the gelling
agents of the invention are used in preparing food products. In
these embodiments, the gelling agents, and gelled products
containing them, may be prepared by first forming a dispersion
comprising water and preferably an edible plasticiser, most
preferably glycerol, with the dispersion having a pH in the range
of about 6.1 to about 8.0. It is preferred that the pH is about
7.5. It is generally desirable that the pH be within the above
range when the gelling agent is to be incorporated into a food
product, as the resulting gel may be waxy and brittle if the pH is
lower than this, or may be unpalatable if the pH is above the upper
limit of the range.
[0030] Suitable buffers to achieve this pH will be apparent to
those skilled in the art. However, a preferred buffer is a
combination of sodium citrate, calcium carbonate and sodium
carbonate. It is preferred that the sodium citrate is present in an
amount of about 1.0% to 2.0%, more preferably about 2.0%, by weight
of the resulting gel, that the sodium carbonate is present in an
amount of about 0.2% to 0.8%, more preferably about 0.4%, by weight
of the gel, and that the calcium carbonate is present in an amount
of about 0.4% to 1.0%, more preferably about 0.8% by weight of the
gel.
[0031] It should also be noted that the calcium carbonate, as well
as acting as a buffer, acts as a texture modifier, resulting in a
gel with a firmer texture, which is desirable when the gel is to be
used as a confectionery product such as a wine gum. The firmer
texture is believed to result from interaction between the calcium
ion and the casein.
[0032] In one preferred embodiment of the invention, glycerol is
present in an amount of about 40% to about 55% by weight of the
gelled product. Glycerol is a humectant and acts as a plasticiser
in the gel. Thus, the more glycerol present, the softer the gel.
The above range of glycerol concentrations has been found to be
desirable for preparing gelled food products having a texture
suitable for confectionery products such as wine gums. Of course,
for other applications, a harder or softer gel may be desirable and
the glycerol concentration should be adjusted accordingly.
[0033] The water acts to disperse the buffer. In the preferred
embodiment of the invention mentioned above, in which the gelled
product is suitable for use as a winegum type product, sufficient
water is added so that water is present in an amount of about 26.7%
to 34.6% by weight of the gel, more preferably about 30.2% by
weight.
[0034] It is also preferred that the casein is washed before use in
order to remove low molecular weight material. The presence of such
low molecular weight material may result in the product having a
bitter aftertaste. A suitable method of washing the casein is to
use distilled water, preferably at a ratio of about 20:1
water:casein. The water and the casein are mixed together, and the
mixture stirred for approximately one hour, the temperature then
increased slowly to 30 C. and held for approximately 30 minutes.
The mixture is then put on ice, stirred for a further two hours and
the small molecular weight casein is removed by filtration, that
is, it remains in the filtrate. Other suitable methods of washing
the casein will be apparent to those skilled in the art.
[0035] The amount of water present significantly influences the
texture of the gel if too much water is added the resulting gel may
be unacceptably soft for a particular application, whereas too
little water will result in a gel which is too hard. Again, the
amount of water added will need to be adjusted for the particular
application to which the gelling agent is to be put.
[0036] The mixture of the buffer, glycerol and water is then
preferably heated to about 40 C., and stirred until the buffer is
dispersed. Once the buffer has been dispersed, casein is added to
the mixture. The casein should be added sufficiently slowly to
avoid the formation of lumps. In the preferred embodiment described
above, the proportion of casein in the gel is about 18% by weight.
Concentrations of casein significantly lower than this may produce
gels which are too soft and fail to hold their shape after gelling,
whereas significantly higher concentrations may produce gels which
are too hard and do not have the `gummy` texture required when the
product is to be a confectionery product such as a wine gum. It
will of course be appreciated that gels which are either soft or
hard will be appropriate for applications other than as a
confectionery such as a wine gum. Gels which contain more or less
than 18% by weight of modified casein are therefore in no way
excluded from the present invention.
[0037] It should be noted that, if, as is preferred, the casein is
washed, the washed casein will retain a significant amount of
water. This means that the water content of the casein will need to
be determined and the amounts of water and casein adjusted
accordingly, to give the desired proportions of water and casein in
the composition.
[0038] After the casein has been added, the mixture should continue
to be stirred. In addition, the mixture is heated to a sufficient
temperature and for a sufficient time to disrupt the native
structure of the casein sufficiently to allow gel formation to
occur. It is preferred that the mixture be heated until the
temperature reaches about 100 C., more preferably about 112 C., or
when foaming lessens. The heating time required will depend on the
rate of heating, but in practice, a heating time of between about 6
and 13 minutes will usually be sufficient.
[0039] The resulting solution, which is the gelling agent, is then
removed from the heat. When the gelled product is to be a
winegum-type confectionery, it is also preferred that additional
components are then added to the solution. These preferred
additional components are:
[0040] (1) a sweetening agent. A preferred sweetening agent is a
combination of fructose and aspartame. However, alternative
sweetening agents (both nutritive and non-nutritive) will be known
to persons skilled in the art, and may also be used. A
concentration of fructose of about 6.0% to about 10.0% by weight of
the gel, most preferably about 8.0% by weight, and aspartame, in an
amount of about 0.1% by weight of the gel have been found to
produce an acceptable level of sweetness. However, the amounts of
the sweetening agents may of course be adjusted depending on the
desired level of sweetness in the gel.
[0041] (2) a flavor modifier which reduces bitterness. As the
casein molecule suffers significant damage during heating, the
resultant gel may have a bitter aftertaste. The use of a suitable
flavor modifier will eliminate this. In the preferred embodiment,
the flavor modifier is maltol (3-hydroxy-2-methyl-4-pyrone),
present in an amount of about 0.1% by weight of the gel. Maltol
minimizes bitterness and enhances sweetness.
[0042] (3) a texture modifier. A particularly preferred texture
modifier which has been found to improve the texture of the gel is
carrageenan, which is preferably added in an amount of about 0.15%
to about 0.25% by weight of the gel. It will be appreciated by
persons skilled in the art that alternative texture modifiers, for
example gums such as carboxy methyl cellulose, may also be
used.
[0043] Components (1) to (3) are stirred into the solution after it
has been removed from the heat, until all components have been
dispersed. If desired, food grade colorings and/or flavorings may
then also be added.
[0044] The resulting mixture is then allowed to cool and set. It is
preferred that the mixture be poured into a mould so that the gel
sets in a desired shape. When the gelled product is to be a
winegum-type confectionery, if desired, the gelled product can be
coated with an agent which hardens the outside of the gel. If such
a coating is desired, then approximately one hour after pouring,
the gelled product can be removed from the mould and coated with
the hardening agent. A preferred hardening agent is a citric
acid/calcium citrate dip, consisting of an aqueous solution
comprising about 15% by weight citric acid and 1% by weight calcium
citrate. The pH of the dip is preferably about 2.0, which is lower
than the isoelectric point of casein (pH 4.5).
EXAMPLE 1
[0045]
1 Component Percentage (by weight) Glycerol 40.0 Water 10.7 Washed
casein 37.1 Fructose 8.8 Sodium citrate 2.0 Calcium carbonate 0.8
Sodium carbonate 0.4 Carrageenan 0.2 Flavour 0.2 Maltol 0.1
Aspartame 0.1 Colour 0.003 Dip Water 74.0 Citric acid 15.0
[0046] Method
[0047] (1) Casein and distilled water were stirred for one hour at
a 20:1 ratio water:casein. The temperature was increased slowly to
30 C. and held for 30 minutes. The sample was then put on ice and
stirred for a further 2 hours and filtered. A moisture
determination of the casein indicated an average moisture content
of 63.4% and the above formulation was calculated to provide a
final moisture content of 30.2% and a casein content of 18.0%.
[0048] (2) The sodium citrate, sodium carbonate and calcium
carbonate were added to the glycerol and water. The mixture was
heated to 40 C. and stirred until dispersed.
[0049] (3) The washed casein was added slowly to avoid the
formation of lumps.
[0050] (4) Stirring was continued and the mixture was heated until
the temperature reached 110 C. to 112 C. or until foaming
stopped.
[0051] (5) The mixture was removed from the heat and the following
were stirred in until all dispersed: carrageenan, fructose, maltol
and aspartame. The colour and flavour were then added.
[0052] (6) The mixture was poured into a mould and left for one
hour. The gel was removed from the mould and placed in a citric
acid/calcium citrate dip for ten minutes.
[0053] The resulting gelled product had a texture and flavour
suitable for use as a winegum type confectionery product.
[0054] Non-food applications
[0055] As noted above, the gelling agents of the present invention
may also be used in products other than food products, for example
as part of a delivery matrix. In such products, a matrix comprising
the modified casein encapsulates an active agent for which a slow
or controlled release from the composition is desired.
[0056] The delivery matrices comprising the gelling agents of the
present invention may conveniently be prepared by first preparing a
modified casein matrix, melting the matrix, adding the active agent
and any other desired ingredients (such as an emulsifier if
required), and then allowing the mixture to cool and set into a
desired shape.
[0057] The modified casein matrix may generally be prepared by
heating casein in the presence of water and preferably a
plasticiser, and at a pH of about 6.1 to about 10.10. It is
preferred that the heating be carried out under basic conditions,
and preferably at a pH of about 9.7. One preferred buffer which may
be used to achieve the desired pH is sodium carbonate, but other
buffers, such as potassium carbonate, trisodium phosphate and
calcium hydroxide may also be used.
[0058] It is preferred that the plasticiser used is glycerol, but
other plasticisers, such as sorbitol, may also be used and are by
no means excluded from the invention.
[0059] It is also generally preferred that the casein be heated in
the presence of a cross-linking agent such as dimethyl adipate. The
use of a cross-linking agent increases the molecular weight of the
modified casein and also decreases its solubility, resulting in a
firmer gel. These properties are generally desirable when the
gelling agents of the invention are to be used in delivery
matrices.
[0060] The preferred method of preparation is to dissolve the
buffer in water, add the plasticiser and the cross-linking agent,
and heat the mixture to 50 C. before adding the casein. Once the
casein is added, the mixture is heated further, preferably to
around 130 C., and continued until the casein is cross-linked
sufficiently to reduce solubility. Following the heating, the
mixture is allowed to cool and set into a desired shape. An active
agent can then be incorporated into the matrix, with the aid of an
emulsifier if required, by melting the matrix together with the
emulsifier (preferably at a temperature of around 70 C.-80 C.) and
mixing in the active agent until homogeneity is achieved. An
example of a suitable emulsifier is a mixture of 80% Datem (mono-
and diglyceride monoacetyl and diacetyl tartaric acid)/20% Calcium
phosphate, although other suitable emulsifiers will be apparent to
those skilled in the art. The mixture may then be moulded into the
desired shape.
[0061] It will be appreciated that the active agent can be any
substance which it is desired to incorporate in a delivery matrix.
For example, the active agent could be a pharmaceutical.
Alternatively, it could be an insect or animal attractant or
repellant, as in the examples which follow.
[0062] The relative amounts of the components used in preparing the
modified casein matrix will again depend on the end use to which
the gelled product is to be put. However, when the gelled product
is to be a delivery matrix incorporating an active agent such as an
animal attractant or repellent, an example of a suitable matrix
formulation is as follows: about 34% glycerol, about 32.6% lactic
acid casein, about 21.7% water, about 6.5% sodium carbonate and
about 5.2% dimethyl adipate.
[0063] The relative proportions of the modified casein matrix,
active agent and emulsifier in the final gelled product will also
depend on the nature of the active agent and the end use to which
the product is to be put. Generally, it has been found that active
agent can be incorporated satisfactorily into the modified casein
matrix at a weight ratio of up to about 1:10 active agent:modified
casein matrix. For example, a suitable composition may comprise
around 5% by weight active agent, 1% emulsifier and 94% modified
casein matrix. Emulsification difficulties may be experienced if
the concentration of active agent is much higher, for example
around 20% by weight.
[0064] It should be noted that, especially when relatively
chemically reactive active agents are being used, it may also be
desirable to decrease the pH of the modified casein matrix to a
more neutral level, to minimize the risk of the active agent
undergoing chemical modification as a result of the relatively high
pH of the modified casein matrix. Glucono-d-lactone is the
preferred acid for achieving the decrease in pH because of its low
solubility and because it brings about a slow decrease in pH.
However, other weak organic acids such as citric acid may also be
used; these would have the advantage of being less expensive than
glucono-d-lactone.
EXAMPLE 2
Entrapped Crayfish Attractant
[0065]
2 Matrix Formulation Component % (w/w) Glycerol 34.0 Lactic Acid
Casein 32.6 Water 21.7 Sodium carbonate 6.5 Dimethyl adipate
5.2
[0066] Method of preparation of matrix
[0067] The sodium carbonate was dissolved in the water; glycerol
and dimethyl adipate were added and stirred. The mixture was heated
to 50 C., the casein added and heating continued to 130 C. The
mixture was poured onto a board, flattened and left to cool.
[0068] The cray attractant was incorporated into the matrix with
the aid of an emulsifier in the proportions outlined below:
3 Component % (w/w) Matrix 94.0 Emulsifier 1.0 (80% Datem/20%
Ca.sub.3PO.sub.4) Cray attractant 4.0
[0069] The attractant was occluded using the following method:
[0070] The matrix was cut into small pieces and heated with the
emulsifier in a crucible in a water bath. The mass was heated until
the matrix had melted (temperature between 70.degree. C. and
80.degree. C.). The mass was mixed until homogeneous. The mass was
removed from the heat and the attractant was weighed directly into
the mass and mixed until a homogeneous, with extra heating to
facilitate mixing. The mass was removed from the crucible and
moulded into the desired shape.
[0071] Further compositions were prepared, varying the proportion
of cray attractant (20%, 10% and 1% attractant). These formulations
were prepared using the same method as described above but with the
following modification: the cray attractant was weighed onto a
small piece of paraffin film (<0.01 g) then added to the matrix
without requiring removal of the matrix from the heat,. These
formulations were as follows:
4 Formulation (weight in grams) Component 1 2 3 Matrix 19.5 22.0
24.25 Emulsifier 0.5 0.5 0.5 (80% Datem/20% Ca.sub.3PO.sub.4) Cray
attractant 5.0 2.5 0.25
[0072] Three further formulations incorporating the cray attractant
were prepared, but having a pH of about 6, 7 and 8 respectively.
These formulations were prepared using the same method described
above (for formulations 1 to 3) but with the modification that
glucono-d-lactone was added at the same time as the cray
attractant. These formulations were as follows:
5 Formulation (weight in grams) Component 4 5 6 Matrix 22.0 22.0
22.0 Emulsifier 0.5 0.5 0.5 (80% Datem/20% Ca.sub.3PO.sub.4) Cray
attractant 2.5 2.5 2.5 Glucono-d-lactone 2.57 3.06 3.37 pH
(approximate) 8 7 6
[0073] It was noted that the practice of weighing the attractant
onto a small piece of paraffin film and adding it directly to the
molten matrix, as opposed to removing the matrix from the heat and
weighing the extract directly into the mass, resulting in the
sample produced being more homogeneous, more cohesive and less
honey comb like.
[0074] The resulting composition can be used to attract crayfish by
placing the composition in craypots. It is believed the attractant
will release slowly from the composition and will therefore have
the advantage of lasting for a considerable time, generally around
two days.
EXAMPLE 3
Entrapped Tom Cat Pheromone
[0075] A composition containing entrapped tom cat pheromone was
prepared, having the following formulation:
6 Component Weight (g) % (w/w) Casein matrix 21.25 86.91 Vegetable
oil 2.00 8.18 Acetone 1.00 4.09 Tom cat pheromone 0.20 0.82
[0076] Method of preparation
[0077] The casein matrix was prepared using the same method as
described above in Example 2.
[0078] The tom cat pheromone was dispersed in the acetone and then
blended with the vegetable oil. The casein matrix was melted and
the tom cat pheromone, acetone and vegetable oil were added and
mixed until homogeneous. The base was then moulded into the desired
shape.
[0079] The resulting composition is believed to release tom cat
pheromone at a slow rate. Without wishing to be bound by any
theory, it is believed the active ingredient will diffuse through
the casein matrix and volatilise. As herbivores are believed to be
repelled by the scent of carnivore pheromones, it is envisaged that
the composition has potential utility in repelling herbivores. For
example, discs of the composition can be attached to trees (eg pine
seedlings) which require protection from herbivores such as
possums.
EXAMPLE 4
Entrapped Mink Anal Gland Pheromone
[0080] A composition in the form of discs incorporating mink anal
gland pheromone (3,3-dimethyl-1,2-dithiolane (DMDT)) was prepared,
using the method described above in Example 2 (entrapped cray
attractant).
[0081] The formulation for the composition was as follows:
7 Component % (w/w) Casein matrix 90.8 (80% Datem/20%
Ca.sub.3PO.sub.4) 2.0 DMDT 7.2
[0082] Water was added at a ratio of 1:5 water to casein matrix, to
aid the melting of the casein matrix. The excess water was removed
from the finished discs by drying over silica gel at room
temperature.
[0083] DMDT is a carnivore odor which appears to induce a fear
response in possums. The compositions containing entrapped DMDT are
therefore believed to be potentially useful as a repellent for
herbivores. In particular, they may be attached to pine seedlings
in order to repel possums from the seedlings.
EXAMPLE 5
Entrapped Stoat Anal Gland Attractant
[0084] Male and female stoat anal gland extracts were incorporated
into the casein matrix at a rate of 1%. To lower the melting point
of the casein matrix the formulation was altered to include
gelatine. The modified casein matrix formulation is as follows:
8 Component % (weight/weight) glycerol 34.0 casein 27.7 water 21.9
sodium carbonate 6.5 dimethlyadipate 5.0 gelatine 4.9
[0085] The composition of the finished products were as
follows:
9 Component % (weight/weight) casein matrix 97.0 emulsifier (80%
Datem/20% Ca.sub.3PO.sub.4) 2.0 male stoat anal gland extract 1.0
casein matrix 97.0 emulsifier (80% Datem/20% Ca.sub.3PO.sub.4) 2.0
female stoat anal gland extract 1.0
[0086] Water was added at a ratio of 1:5 water to casein, to aid
the melting of the casein matrix. The casein matrix and emulsifier
were melted at 55.degree. C., mixed until visually homogenous, the
temperature was adjusted to 50.degree. C., the extract added and
gently mixed. The mass was then cut to the desirable shape and
cooled. The excess water was removed from the finished squares by
drying over silica gel.
EXAMPLE 6
Entrapped Rat Repellent
[0087] Two repellents were occluded in a casein matrix. The two
chemicals were 3-(S-methyl)-3-methylbutan-1-ol and 3-isopentenyl
methyl sulphide.
[0088] The casein matrix used for the rat repellents was the same
as that used for the stoat anal glands.
[0089] The composition of the finished products were as
follows:
10 Component % (weight/weight) casein matrix 93.0 emulsifier (80%
Datem/20% Ca.sub.3PO.sub.4) 2.0 3-(S-methyl)-3-methylbutan-1-ol 5.0
casein matrix 93.0 emulsifier (80% Datem/20% Ca.sub.3PO.sub.4) 2.0
3-isopentenyl methyl sulphide 5.0
[0090] Water was added at a ratio of 1:5 water to casein, to aid
the melting of the casein matrix. The casein matrix and emulsifier
were melted at 55.degree. C., mixed until visually homogenous, the
temperature was adjusted to 50.degree. C., the extract added and
gently mixed. The mass was then cut to the desired shape and
cooled. The excess water was removed from the finished squares by
drying over silica gel.
EXAMPLE 7
Entrapped Fly Attractant
[0091] A fly attractant was incorporated into two matrices: a solid
gel matrix (as above), and a thick paste-like matrix.
[0092] A. Gel product
[0093] The product was prepared as per the stoat product with the
exception the attractant was added at 2% and 10%.
[0094] The composition of the products were as follows:
11 Component % (weight/weight) casein matrix 96.0 emulsifier (80%
Datem/20% Ca.sub.3PO.sub.4) 2.0 Fly attractant 2.0 casein matrix
88.0 emulsifier (80% Datem/20% Ca.sub.3PO.sub.4) 2.0 Fly attractant
10.0
[0095] The product was prepared as per the stoat product with one
exception. Sodium sulfide was dispersed in the extra water (added
to aid melting at a rate of 1.5% (w/w) of the fly attractant.
[0096] Due to the highly volatile nature of the fly attractant
components losses in the manufacturing process were believed to be
in the range of 50%. These products successfully attracted flies
into traps in a field trial conducted in North Taranaki for a
minimum of four weeks.
[0097] B. Paste product
[0098] To minimize the high losses of fly attractant associated
with the above product, the casein matrix was reformulated to
produce a paste-type product at room temperature (it gels at low
temperatures).
[0099] The modified formulation is as follows:
12 Component % (weight/weight) Plasticiser (propylene glycol) 42.3
casein 18.5 water 22.9 maltodextrin (DE 10) 11.0 thin boiling
starch (TB840) 3.7 sodium carbonate 1.0 calcium carbonate 0.5
xanthan gum 0.1
[0100] The casein paste is prepared by the following procedure:
[0101] The water and propylene glycol are mixed;
[0102] The casein, thin boiling starch (TB840), sodium carbonate,
calcium carbonate and xanthan gum are dry blended (powdered
mix);
[0103] The powdered mix is dispersed in the water and propylene
glycol and mixed until free of lumps;
[0104] The mixture is heated to between 95.degree. C. and
100.degree. C. for 10 minutes;
[0105] The maltodextrin (DE 10) is added and mixed until
dispersed;
[0106] The hot mass is cooled to room temperature.
[0107] A fly attractant can be prepared from the above product by
the following method:
[0108] The casein paste matrix is warmed to between 25.degree. C.
and 30.degree. C.;
[0109] the emulsifier and sodium sulphide dispersed in the
matrix;
[0110] the attractant added and mixed until dispersed.
[0111] At this stage the mass can either packed off directly into a
suitable tube or heated to 35.degree. C. (to facilitate filling)
then packed off into a suitable tube.
13 Component % (weight/weight) casein paste matrix 92.925
emulsifier (80% Datem/20% Ca.sub.3PO.sub.4) 2.000 Fly attractant
5.000 sodium sulphide 0.075
[0112] The texture/viscosity of the product can be easily altered,
for example by:
[0113] 1) Substituting propylene glycol for glycerol will increase
the firmness of the final product.
[0114] 2) Altering the ratio of maltodextrin to thin boiling
starch. As the proportion of thin boiling starch is increased the
firmness of the product is increased, alternatively increasing the
proportion of maltodextrin softens the product.
INDUSTRIAL APPLICATION
[0115] It is believed that the novel gelling agents and gels
according to the present invention will find widespread acceptance.
For example, they are suitable for use in food products such as
confectionery, as described above. It is believed that the gelled
products according to the invention will possess enhanced textural
properties on storage as compared with currently available gels
formed from gelatine.
[0116] In other applications, the gelling agents may be employed in
the preparation of non-edible gels. Such gels may for example form
part of a delivery matrix, as described above.
Pharmaceutical/medical applications are also possible.
[0117] Those persons skilled in the art will appreciate that the
above description is exemplary only and that variations and
modifications are possible without departing from the scope of the
invention.
* * * * *